DESCRIPTION: Many studies have shown that, among adults undergoing cardiac surgery, females have a higher risk-adjusted mortality rate. The mechanisms through which gender affects cardiovascular outcomes remain unclear. Little is known regarding the role of gender in determining the outcomes for children undergoing surgical repair of congenital heart disease. In a recent study using the 1995-1997 hospital discharge data from California, we found, in pediatric cardiac surgery, females have 51 percent higher risk-adjusted inhospital mortality than males. We have designed the current study using 15 years of data from California to explore the possible causes for higher inhospital mortality in female infants and children undergoing cardiac surgery. The goal of this project is to investigate gender differences in cardiovascular outcomes for children and evaluates the possible causes for gender differences. Hospital discharge data 1985-1999 from the California Office of Statewide Health Planning and Development (OSHPD) will be used to conduct this analysis. We will select children older than 18 years of age who underwent cardiac surgery defined by ICD9-CM codes. Logistic regression will be conducted to calculate the odds ratio for mortality comparing females with males while controlling for other patient, medical and healthcare system variables. We will test four specific hypotheses explaining the higher inhospital mortality in females: 1) Females have more associated cardiac and non-cardiac conditions than males resulting in higher mortality from cardiac surgery; 2) Males are discharged early therefore have more out of-hospital deaths than females; 3) There is gender inequality in utilization of healthcare services such that females use fewer services resulting in poorer outcomes; 4) There are unmeasured biological or other differences between male and female that affect outcomes of cardiac surgery. This study will explore the mechanisms through which gender affects outcomes of cardiac surgery, including biological differences between males and females, and issues related to health service utilization and delivery. This project will provide important information to clinicians and healthcare policymakers, and lead to future research on eliminating the gender differences in cardiovascular outcomes.